Thanks for the prompt reply Christian.

The short answer is I don't know, but you have a point.
The longer answer is I was asked to go down and give them a hand, I didn't
know they wanted me to plan the system, they've already bought the boiler a
Valiant eco 82? the outside temporary tap fills a kettle pretty quickly, but
I didn't think to check the flow rate...too many other problems to sort out

Cheers,

Jeff


"Christian McArdle" wrote in message
. net...
The owner has been advised by the builder that a 15mm supply will be
adequate,

As a general rule, I've only used 15mm for basins, toilets and appliances.
Showers and baths get 22mm. However, you appear to be installing a combi
boiler. If the mains pressure really is low, you should check that it is
still enough for a mains pressure installation. What sort of flow rate can
be supplied?

Christian.